First, I tried to capture dusk flats with CCDAutopilot. Worked REALLY well (actually seemed to be faster then with the NUC - I could almost capture 20x5 (Ha, SIII, OII, Lum, Red, Green, Blue) flats!!!

Then I started with setting up a new model from scratch:

Home

Closed Loop Slew to Arcturus, Sync

20 point model - adjust polar alignment

50 point model - adjust polar alignment

270 point super model - adjust polar alignment

recalibrate portable to check polar alignment

Final PA:

MA: 1.1 arcsec (!!!)

ME: -53.7 arcsec

Then I wanted to use PHD2 to log tracking errors. But when I tried the initial calibration, I had the issue again that PHD2 didn't move the mount in the proper directions. Read through various forums again and it seemed as if people didn't enable PulseGuiding but DirectGuide. Did that - and then everything worked!!!

Tried to capture a new PE curve, but with the same results (PE got better - but only marginally). But while logging this, I could see that the tracking error was REALLY small (the guiding star stayed in the subframe during the 25 min run - and only moved a little).

So, finally, I enabled guiding in PHD2 and let the mount run (had to go to bed). The next morning, I checked with PHDLab:

Clearly, I have to tune my guiding parameters in PHD2, but an RMS error of 0.7arcsec in 3+ hours isn't too bad.